In information collecting systems, e.g. monitoring systems, surveillance systems, etc, it is increasingly common to remotely control the system. The main reason for this is that reading or viewing results from information collecting devices is facilitated as it becomes possible to access the information from more or less anywhere. Moreover, the system may be controlled or administrated from virtually any location.
In these systems information generated or collected at an information collecting site is normally stored at a central site supporting a plurality of information collecting sites where the equipment enabling remote access are arranged and are provided with large storage capacity. Such systems are described in the International applications WO 2006/073348 and WO 2007/073314 by Axis AB. Using such centralized storage may be advantageous in that only one site need to be considered in view of protecting information and the equipment storing the information from fire, earthquakes, power interruptions, criminals stealing equipment and/or information. However, the traffic load to the network connecting the centralized storage to the network becomes high and the risk of loosing crucial information when locating all storage capacity at one single site is evident.
The problem of the high traffic load becomes more critical as the requirement of more frequent data updates and higher information collecting capacity at the monitoring devices, e.g. the resolution and frame rate of video cameras used for monitoring or surveillance increases dramatically. Hence, from some information collecting sites the bandwidth is not enough for transfer of the desired amount of information at the desired frequency.
In US 2006/0161960, a security centre appliance is arranged at the information collecting site connecting direct to information collecting devices, in this case wireless IP cameras, thereby avoiding the trouble of bandwidth restrictions on the line out from an information collecting site. However, you will have to set up a security centre appliance at each and every information collecting site. Moreover, setting up and maintaining a security centre appliance is complicated.
In US 2006/0199734, a plurality of data storing servers are connected on a communication network and a plurality of cameras connected with the communication network are divided into a plurality of groups, and the respective groups are related to the respective data storing servers in correspondence. The respective data storing servers import images from the cameras belonging to the corresponding groups and store the imported images.